1. Field of the Invention
The present invention generally relates to a panel clip assembly and more particularly, to a panel clip assembly for use with skylight, roof or wall panels having improved strength, improved noise reduction and improved allowance for longitudinal and transverse panel movement in response to thermal expansion and contraction of the panels.
2. Description of the Prior Art
It is well known to secure standing seam roof and wall panels, including translucent panels, to purlin or girt substrates using hidden clips and related clip assemblies. Examples of various of these clip assemblies are shown in U.S. Pat. Nos. 4,184,299, 4,193,247, 4,261,998, 4,495,743, 4,543,760, 4,575,983, 5,001,882, 5,181,360, 5,222,341, 5,363,624, 5,606,838 and 6,164,024. As noted in this prior art, a continuing problem has existed concerning the impact of thermal forces (expansion and contraction) on panels supported and joined together by clip assemblies. By way of example, if clip assemblies are too rigid, damage may occur to the panels or clip assemblies during thermal expansion or contraction. In addition, undesirable noises and wear are caused by frictional panel movement resulting from thermal and other forces, i.e. panels rubbing against the clip assembly, against the fasteners that hold the clip assembly, and against the substrates. Our design addresses these problems.
Also, in response to these concerns, some prior clip assemblies have been designed with two interlocking but moveable pieces. More specifically, clip assemblies have been designed with a lower base member that is fixed to a substrate and an upper clip member which is attached to the base member in such a manner that the upper clip member can slide parallel to the seam created by adjoining panel members. See, e.g., U.S. Pat. No. 4,575,983. This sliding movement helps relieve expansion and contraction forces that run parallel to the panel seam.
Existing clip assemblies continue to experience problems from thermal forces, however. In particular, existing clip assemblies are too rigid in respect to, and do not adequately address, thermal forces that are applied perpendicular to panel seams (and perpendicular to the sliding movement allowed for in the clip assemblies described above). Thus, wear and damage problems from such forces continue to exist. In addition, unwanted frictional noises have not been satisfactorily eliminated or reduced.
Further, there exists a need for an improved clip assembly which satisfactorily allows for and addresses a range of panel movements and which raises up and supports the panels at their undersides sufficient to allow the panels to avoid rubbing contact with the substrate, on which the panel clips are mounted. No existing clip assembly addresses the need for an assembly that includes these features and that allows for and addresses various ranges of movement experienced by panels and that also eliminates or reduces corresponding frictional noises and wear.